1. Field of the Invention
This invention relates to a buffer memory self-diagnosis method for an information signal processing apparatus, for example, an optical disc apparatus utilized as an external storage for a computer.
2. Description of the Related Art
Heretofore, an optical disc apparatus is used as an external storage, and is capable of recording mass data.
After the power has been turned on, the optical disc apparatus used as an external storage for a computer executes predetermined self-diagnostic program, so that the important data can be surely recorded and reproduced.
For example, if it is used a buffer memory utilized as a cache memory which is a fault therein, the data outputted from a host computer may be incorrectly recorded, and the correctly reproduced data may be incorrectly outputted.
Therefore, this kind of optical disc apparatus executes the self-diagnostic program to confirm that it is in good order in the buffer memory and the like, and thereafter the data is written and read.
Meanwhile, if the capacity of a buffer memory is bulked up to enlarge the region utilized as a cache memory, the mean access time of the optical disc apparatus can be shortened, whereby the facilities can be increased.
However, if the buffer memory is bulked up, much time for self-diagnosis is required, so that there occurs a problem that the time from the power on to the start of access, that is, the initial access time, will become longer.
Particularly, in some computers capable of connecting this kind of the optical disc apparatus, there may be one which decides any operation for the case where the optical apparatus is not connected thereto, if there is unable to access the optical disc apparatus during a predetermined time after the power on. Therefore the optical disc apparatus may be unutilized, if the initial access time becomes longer carelessly.